It was recombined as Stegomastodon waringi by Holand (1920) and Alberdi and Prado (1995); it was synonymized subjectively with Haplomastodon chimborazi by Ficarelli (1994); it was synonymized subjectively with Notiomastodon platensis by Mothé et al. (2012).

If no rank is listed, the taxon is considered an unranked clade in modern classifications. Ranks may be repeated or presented in the wrong order because authors working on different parts of the classification may disagree about how to rank taxa.

A species of gomphothere that differs from the species of Rhynchotherium
and Gomphotherium in having no lower tusks. It differs from the species of Cuvieronius by the absence of spiraled torsion and spiral enamel band in upper tusks. It differs from the species of Rhynchotherium, Gomphotherium, and Cuvieronius by having a brachycephalic skull with a high parieto-occipital region (“elephantoid” condition, also cited by Ferretti, 2008), and molar teeth
more complex and with larger number of cones. It differs from Stegomastodon texanus and the species of Sinomastodon by the loss of the supraorbitals foramen. Differs from S. texanus by possessing a higher land more anteriorly oriented ascending ramus and the posterior opening of the mandibular canal (mandibular foramen), placed more dorsal on the medial side of the ascending ramus.